﻿using System;
using System.Globalization;
using System.Windows.Data;
using System.Windows.Markup;

namespace MugenMvvmToolkit.Converters
{
    /// <summary>
    ///     This converter reverses a Boolean value (True == False, False == True).
    /// </summary>
#if WPF
    [ValueConversion(typeof(bool), typeof(bool))]
    [MarkupExtensionReturnType(typeof(InverseBooleanConverter))]
#endif
    public sealed class InverseBooleanConverter :
#if WPF
 MarkupExtension,
#endif
 IValueConverter
    {
        #region Implementation of IValueConverter

        /// <summary>
        ///     Converts a value.
        /// </summary>
        /// <returns>
        ///     A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        /// <param name="value">
        ///     The value produced by the binding source.
        /// </param>
        /// <param name="targetType">
        ///     The type of the binding target property.
        /// </param>
        /// <param name="parameter">
        ///     The converter parameter to use.
        /// </param>
        /// <param name="culture">
        ///     The culture to use in the converter.
        /// </param>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            Should.BeBooleanOrNullable(targetType, "targetType");
            var b = (bool?)value;
            if (b.HasValue)
                return !b.Value;
            return null;
        }

        /// <summary>
        ///     Converts a value.
        /// </summary>
        /// <returns>
        ///     A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        /// <param name="value">
        ///     The value that is produced by the binding target.
        /// </param>
        /// <param name="targetType">
        ///     The type to convert to.
        /// </param>
        /// <param name="parameter">
        ///     The converter parameter to use.
        /// </param>
        /// <param name="culture">
        ///     The culture to use in the converter.
        /// </param>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return Convert(value, targetType, parameter, culture);
        }

        #endregion

#if WPF

        #region Overrides of MarkupExtension

        /// <summary>
        ///     When implemented in a derived class, returns an object that is set as the value of the target property for this markup extension.
        /// </summary>
        /// <returns>
        ///     The object value to set on the property where the extension is applied.
        /// </returns>
        /// <param name="serviceProvider">
        ///     Object that can provide services for the markup extension.
        /// </param>
        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return new InverseBooleanConverter();
        }

        #endregion

#endif
    }
}